A TDD (Time Division Duplexing, Time Division Duplexing) system sends and receives information on one frequency channel, but the receiving and the sending of the information use different time slots of one frequency carrier. The data transmission of the downlink subframe corresponds to UCI such as response information, which is generally fed back through an uplink subframe.
A LTE (Long Term Evolution, Long Term Evolution) TDD system includes 7 uplink-downlink subframe configurations. In some of uplink-downlink subframe configurations, the number of downlink subframes is greater than the number of uplink subframes, and it is possible that the UCI corresponding to data transmission of multiple downlink subframes need to be fed back on the same uplink subframe. The UCI is generally encoded through RM (Reed Muller, Reed Muller) (32, O) code before being transmitted to the base station.
An LTE-A (Long Term Evolution Advanced, Long Term Evolution Advanced) system is a further evolved and enhanced LTE system. In an LTE-A TDD system, carrier aggregation is introduced. When a terminal accesses multiple component carriers simultaneously, the terminal needs to feed back UCI on the same uplink carrier, where the UCI is UCI of multiple downlink subframes from multiple downlink component carriers. Therefore, the bits occupied by UCI on one uplink subframe increase significantly. When the number of bits occupied by UCI exceeds the maximum number of bits (11 bits) supported by RM (32, O) code, it is urgent to put forward a solution to transmitting UCI, which is lacking in the prior art.